<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>伪类</title>
		<style type="text/css">
			input:focus{
				background-color: #DB7093;
				}
				input:hover{
					background-color: #7FFFD4;
					}
					button:active{
						margin: 3px;
						background-color: #0000FF;
						}
		</style>
	</head>
	<body>
		<input type="password"  />
		<button type="button">登录</button>
	</body>
</html>
